Kinetic modelling of Maillard reaction products and protein content during roasting of coffee beans

In this study, the effects of various roasting methods on the alpha-dicarbonyl compounds (alpha-DCs), melanoidins, crude proteins, and colour value of roasted coffee beans (Coffea arabica) were analysed. The concentration of alpha-DCs in the coffee samples significantly changed (p < 0.05) during roasting, while that of melanoidins increased with roasting time in all roasting methods regardless of temperature. Crude protein decreased as roasting time increased. Through kinetic modelling, pan roasting was found to increase the rate constant of alpha-DCs, melanoidins, and crude proteins by up to 62.6%, 9.3%, and 33.3%, respectively. Air frying was observed to decrease the activation energy of alpha-DCs, melanoidins, and crude proteins by up to 57.8%, 22.3%, and 12.6%, respectively. The pan roasting method was shown to minimise alpha-DCs by up to 15% during medium roasting of coffee beans.